Both my kids are good at math. They did for awhile Singapore math workbooks after school. At one point, I remember that my younger son was in kindy or first grade, and although he is a very good reader, he had trouble reading the math questions in the Singapore math book well enough to understand them to do.
We abandoned that for awhile until his reading improved enough to understand the questions.
Your child is only 5, which is very young. If you can instill in him a love of reading, that is probably all you need at this early point.
